The invention relates generally to the field of offset printing and, more specifically, to positioning jigs which are useful for accurately positioning copy material in a photographic print plate maker.
Previous methods for offset printing involve making a photographic negative of the original print material from which the offset print plate is then made. More recently, photo-direct plate makers have been developed which eliminate the intermediate step of making a photographic negative of the original print material. Because they are less expensive to own and operate than other types of print plate makers, photo-direct plate makers have found wide acceptance and use in such business as "Quick-print" shops.
Whether the plate maker is one that produces negative images or is the photo-direct type, accurate alignment of the copy material or ready copy is important in order that the offset print plate can reproduce copies having script which is accurately aligned with the borders of the paper. Accordingly, existing plate makers commonly have positioning lines inscribed on the top facing surface of the copyboard to assist the operator in aligning the copy material. Visual alignment of the copy material is, however, inherently inaccurate and time consuming. Further, due to the size of the copyboard and the shape of the plate maker, it is difficult, if not impossible, for the operator to attain a position directly overhead of the copy material from which accurate visual alignment of the ready copy can be made. As a result, the operator must align the copy material with the positioning lines from a position which is oblique to the line of the camera. The difficulty associated with accurately aligning the copy material from such a position is readily apparent.
In addition to printing copies of larger size documents such as resumes, pamphlets, advertisements, circulars, etc., printers and particularly "Quick-print" shops are frequently called upon to print relatively smaller items which occupy considerably less than the 8 1/2" by 11" standard letter size page. One such frequently printed item are business cards, which characteristically have a 2" by 3 1/2" standard size. Since most printing equipment is not adapted to print on such small sized paper, business cards are printed on 8 1/2" by 11" standard letter size sheets. If only a relatively small number of cards are desired many print shops will print the cards one to a sheet, most of the area of the sheet being wasted material after the actual copy is cut from the sheet. This practice is obviously not economical from the standpoint of the amount of paper which is wasted.
If a relatively large number of business cards or other similar small size copy material is desired, it becomes even more economical to prepare a print plate having thereon several copies of the material to be printed. However, in such situations it is critical that the copies on the print plate be accurately positioned with respect to each other in order that the print material on the printed cards will be properly aligned with the borders of the card. The need for accurate positioning of the copy material in making such a print plate has required that considerable time be spent in alignment, and is for this reason an added cost and a disadvantage.
The technique of placing a plurality of images on a single plate, using only one original, is referred to as "step and repeat". Present methods for making a photographic print plate bearing a plurality of images of the original print material involve making several copies of the original print material from a photographic copier machine and then cutting and pasting the several copies together on one sheet for a single exposure. Another method involves the use of a complicated, costly and time consuming "pin system". "Step and repeat" has also been attempted, more crudely, by measurement location on the copyboard. Methods, such as those just described, are time consuming and require accurate visual alignment of the multiple copies with respect to each other so that the printed material can be easily cut into individual sheets. Due to these disadvantages, "step and repeat" has had very limited acceptance in the quick print industry.